{
    console.log('a',`\u0061`);
    console.log('s',`\u20BB7`);
  
    //用大括号
    console.log('s',`\u{20BB7}`);
  
  
  }

  {
    let s='𠮷';
    console.log('length',s.length);
    console.log('0',s.charAt(0));//第一个字符
    console.log('1',s.charAt(1));//第二个字符
    console.log('at0',s.charCodeAt(0));//第一个码值
    console.log('at1',s.charCodeAt(1));
  
    let s1='𠮷a';
    console.log('length',s1.length);
    console.log('code0',s1.codePointAt(0));
    console.log('code0',s1.codePointAt(0).toString(16));
    console.log('code1',s1.codePointAt(1));
    console.log('code2',s1.codePointAt(2));
  }

  {
    console.log(String.fromCharCode("0x20bb7"));
    console.log(String.fromCodePoint("0x20bb7"));
  }

  {
    let str='\u{20bb7}abc';
    for(let i=0;i<str.length;i++){
      console.log('es5',str[i]);
    }
    for(let code of str){
      console.log('es6',code);
    }
  }
  

  
{
    let str="string";
    console.log('includes',str.includes("c"));
    console.log('start',str.startsWith('str'));
    console.log('end',str.endsWith('ng'));
  }
  

  {
    let str="abc";
    console.log(str.repeat(2));
  }

  {
    let name="list";
    let info="hello world";
    let m=`i am ${name},${info}`;
    console.log(m);
  }

  {
    console.log('1'.padStart(2,'0'));
    console.log('1'.padEnd(2,'0'));
  }


  {
    let user={
      name:'list',
      info:'hello world'
    };
    console.log(abc`i am ${user.name},${user.info}`);
    function abc(s,v1,v2){
      console.log(s,v1,v2);
      return s+v1+v2
    }
  }

  
{
    console.log(String.raw`Hi\n${1+2}`);
    console.log(`Hi\n${1+2}`);
  }